S Haneder

Publications of S Haneder

• [Functional magnetic resonance imaging for evaluation of radiation-induced renal damage].

  Authors: S Haneder, J Boda-Heggemann, S O Schoenberg, H J Michaely

  Der Radiologe. 03/2012; 52(3):243-51.

  The diagnosis of radiation-induced (especially chronic) renal alterations/damage is difficult and currently relies primarily on clinical evaluation. The importance of renal diagnostic evaluation willThe diagnosis of radiation-induced (especially chronic) renal alterations/damage is difficult and currently relies primarily on clinical evaluation. The importance of renal diagnostic evaluation will increase continuously due to the increasing number of long-term survivors after radiotherapy. This article evaluates the potentia diagnostic contribution of magnetic resonance (MR) imaging with a focus on functional MRI. The following functional MRI approaches are briefly presented and evaluated: blood oxygenation level-dependent imaging (BOLD), diffusion-weighted imaging (DWI) or diffusion tensor imaging (DTI), MR perfusion measurements and (23)Na imaging. In summary, only DWI and contrast-enhanced MR perfusion currently seem to be suitable approaches for a broader, clinical implementation. However, up to now valid data from larger patient studies are lacking for both techniques in regard to radiation-induced renal alterations. The BOLD and (23)Na imaging procedures have a huge potential but are currently neither sufficiently evaluated with regard to radiation-induced renal alterations nor technically simple and reliable for implementation into the clinical routine.

• "Number needed to read"--how to facilitate clinical trials in MR-angiography.

  Authors: M Voth, U I Attenberger, A Luckscheiter, S Haneder, T Henzler, S O Schoenberg, C Schwenke, H J Michaely

  European radiology. 10/2010; 21(5):1034-42.

  To evaluate the effect of the number of readers on the statistical results in peripheral MRA. 40 patients with peripheral arterial occlusive disease were included as a sample dataset in this study,To evaluate the effect of the number of readers on the statistical results in peripheral MRA. 40 patients with peripheral arterial occlusive disease were included as a sample dataset in this study, randomly separated into two matched groups with n = 20 patients (group 1--gadobutrol, group 2--gadoterate meglumine) who underwent a continuous table movement MRA of the peripheral vessels at 3 T. Image quality (IQ) of 17 vessel segments was evaluated by 5 independent readers. The effect of the number of readers on significance and statistical power was statistically analyzed. Image quality in group 1 (gadobutrol) ranks significantly higher compared to group 2 (gadoterade meglumine) with a diagnostic IQ in 97% vs. 78% (p < 0.0001). For the diagnostic/non-diagnostic IQ assessment significance was reached with one reader 1/5 times (20%), with two readers in 4/10 (40%), with three readers in 6/10 (60%), with four readers in 4/5 (80%), with five readers in 1/1 (100%). Power considerations showed considerable gain when increasing the number of readers. Increasing the number of readers in a diagnostic MRA-study can be used to achieve a higher power or to decrease the number of subjects included with maintained statistical validity.

• Image quality of T2w-TSE of the abdomen and pelvis with Cartesian or BLADE-type k-space sampling: a retrospective interindividual comparison study.

  Authors: S Haneder, D Dinter, A Gutfleisch, S O Schoenberg, H J Michaely

  European journal of radiology. 02/2010; 79(2):177-82.

  The purpose of this study was to evaluate the image quality of T2-weighted (T2w) imaging of the abdomen and pelvis based on the acquisition of rotating rectangular stripes of k-space data afterThe purpose of this study was to evaluate the image quality of T2-weighted (T2w) imaging of the abdomen and pelvis based on the acquisition of rotating rectangular stripes of k-space data after successive radiofrequency excitation (BLADE technique) in comparison to T2w turbo-spin-echo (TSE) sequences with Cartesian k-space sampling. A total number of 107 patients with MR imaging of the abdomen or the pelvis were included in this retrospective interindividual study. All exams were performed in the clinical routine at 1.5T. The T2w images were randomly performed in BLADE technique or as TSE sequences. Two blinded radiologists assessed the images, presented in a random order, concerning the delineation of the abdominal and the musculoskeletal structures, the artifacts of these structures, and the overall image qualities. For the abdomen the mean overall image quality of the T2w-BLADE was rated 3.2 vs. 3.1 for T2w-TSE (p=0.871). The mean musculoskeletal/visceral artifacts of the T2w-BLADE were scored as 2.9/3.0 vs. 3.2/2.6 for the T2w-TSE (p=0.101/p=0.051). The delineation of the musculoskeletal, respectively of the visceral structures was assessed for the T2w-BLADE as 3.0/3.4 vs. 3.2/3.1 for the T2w-TSE (p=0.263; p=0.185). For the pelvis the mean overall image quality of the T2w-BLADE was 3.4 vs. 2.9 for the T2w-TSE (p=0.005). Furthermore the musculoskeletal/visceral artifacts were assessed with a mean of 3.6/3.3 for the T2w-BLADE vs. 3.0/2.8 for the T2w-TSE (p=0.005; p=0.011). The musculoskeletal/visceral delineation of the T2w-BLADE was rated 3.6/3.4 vs. 3.0/2.8 for the T2w-TSE sequence (p<0.001; p=0.008). In imaging of the pelvis the overall quality of T2w sequences with k-space sampling in BLADE technique was rated significantly superior compared with the standard Cartesian sampling. Similar results were assessed for the reduction of the amount of artifacts and blurring. By contrast, no significant benefit could be demonstrated for the T2w-BLADE in the abdomen.